"You will be the voice of reason," Shannon High says. "You will be the calm, cool, collected surgeon who says what's real and what's not real."

As Snyderman slips off her heels under the desk and plants her red-painted toenails on the chair's base, a wall monitor flashes an MSNBC report on the Jon and Kate divorce. "We're not going to do this," Snyderman declares.

Finding the right tone for "Dr. Nancy," a health and medical show that debuts today on MSNBC, is a challenge for this 52-year-old physician hanging out her shingle in the noisy cable neighborhood. With the health-care debate heating up on Capitol Hill, she hopes to educate as well as entertain.

"I know what it's like to close up the cash register in my practice at the end of the day," Snyderman says. "I know how to explain complicated medical questions without being condescending."

Television doctors, such as ABC's Timothy Johnson and CBS's Jon LaPook, are in demand these days. CNN's Sanjay Gupta, who withdrew as a candidate for surgeon general in March, has been hosting the weekend program "House Call" since 2003. But Snyderman's noontime show is the first daily attempt by a network to mine the intersection between politics and health care.

"Doctors are often treated as gods, and they aren't," says MSNBC President Phil Griffin. "This will break down some of the mythology around doctors and medicine."

With former CNBC business anchor Dylan Ratigan also launching a personality-driven morning show today, MSNBC is down to just five daytime hours of straight news, which once formed a counterpoint to its liberal evening programming. The third-place channel is betting that branded hours will provide an alternative to headline hopscotching.

"There's so much information out there," Griffin says. "What people want is depth, broader conversation, different points of view. We can't win by doing it the same old way."

By tapping NBC's chief medical editor, a former pediatrician and cancer surgeon who says she "hounded" her bosses for a cable show, Griffin is getting a highly opinionated woman who delivers her views with a soothing bedside manner -- most of the time, at least.

On the "Today" show in February, Snyderman ripped into the author of a 1998 study in the Lancet that asserted a link between childhood vaccines and autism -- which the British medical journal later called "fatally flawed." Snyderman, who believes passionately in vaccines, declared: "This guy is a fraud." NBC later removed her from a planned "Dateline" examination of the subject.